US3068815A - Welt attaching machines - Google Patents

Description

Dec. 18, 1962 L. G. MILLER WELT ATTACHING MACHINES 4 Sheets-Sheet 1 Filed Feb. 28 1961 Invenfor I floydQ/Yzller Dec. 18, 1962 G. MILLER WELT ATTACHING MACHINE 4 Sheets-Sheet 2 Filed Feb. 28, 1961 Dec. 18, 1962 L. e. MlLLER WELT ATTACHING MACHINES 4 Sheets-Sheet 3 Filed Feb. 28, 1961 Dec. 18, 1962 L. G. MILLER WELT ATTACHING MACHINES 4 Sheets-Sheet 4 Filed Feb. 28, 1961 United rates Patent 01 3,%S,815 WELT AITACHENG MACS Lloyd G. Miller, Beverly, Mass., assignor to United Shoe Machinery Corporation, Boston, Mass, a corporation of New Jersey Filed Feb. 28, 1961, Ser. No. 92,251 6 Claims. (Cl. 11246) This invention relates generally to improvements in a machine for attaching welts to lasted shoe uppers and sole members, and has particular reference to a machine having mechanism for severing the welt and automatically stopping the machine after a predetermined interval.

The invention is illustrated herein as being applied to a Goodyear welt and inseam sewing machine equipped with a welt severing mechanism which may be actuated, in the case of a sewed heel seat shoe, by a feeler engaging the leading end of the welt first attached to the shoe, as the seam being inserted nears completion; or in the case of a shoe having a welt extending around the forepart only, may be actuated directly by the operator when the welt attaching operation reaches the proper point at the breast portion of the shoe.

A machine of this type is illustrated in United States Letters Patent No. 2,900,933, granted August 25, 1959, to J. P. Carter, which should be referred to for a description of certain parts or" the machine which are associated with the mechanism embodying the invention to be described hereinafter.

. During the attachment of a welt by a machine of this type, to a so-called sewed seat shoe, in which the welt extends completely around the shoe periphery, after the welt has been cut in response to the engagement of the feeler with the leading end of the welt first attached to the shoe, the operator permits the sewing operation to continue until the end of the welt is attached and several stitches are made beyond the point at which the ends of the welt abut. However, in the case of a shoe in which the welt is attached only to the forepart portion of the shoe forward of the heel breast line, commonly referred to as breast-to-breast work, the operator stops the attaching operation almost at the instant the welt is cut, thereby leaving the end portion of the welt unattached for subsequent trimming operations.

Because of the accurate timing required in judging when to terminate the sewing operation after the welt has been cut, the operator of the machine must have considerable training to become proficient in its proper operation. If the sewing is stopped too soon or too late, repair work on the shoe is required, which is time consuming and expensive. In case of thread breakage, it is also important that the machine be stopped immediately to prevent the needle from piercing threadless holes in the welt and innersole rib.

An object of this invention is to provide a machine of the type described in which means is provided for stopping the sewing operation automatically a predetermined time after the welt has been cut.

A further object of the invention is to provide means responsive to the actuation of the welt cutting knife for stopping the machine by releasing the machine-actuating treadle mechanism independently of any action by the operator.

A further object of the invention is to provide means for releasing the machine-actuating treadle mechanism which is actuated automatically by either the action of the welt cutting knife or by thread breakage.

A further object of the invention is to provide automatic means for continuing the sewing operation for a predetermined interval after the welt has been cut, with "ice means for varying said predetermined interval to accommodate either breast-to-breast work or sewed seat work.

(Ether objects of the invention will be apparent to one skilled in the art from the following detailed description of a specific embodiment thereof.

In the drawings:

FIG. 1 is a view in front elevation of a Welt attaching machine embodying the features of the invention;

FIG. 2 is an enlarged view of the operating head of the machine of FIG. 1;

FIG. 3 is an enlarged view of the treadle release mechanism of the machine of FIG. 1;

FIG. 4 is a perspective view of a thread break detecting mechanism;

FIG. 5 is an enlarged view of a portion of the thread break detecting mechanism illustrated in FIG. 4; and

FIG. 6 is a schematic view of the machine controlling mechanisms and their associated electrical circuits.

Referring to the drawings, there is illustrated a welt attaching machine it which is adapted to attach a welt 12 to the periphery of a lasted shoe 14 (see FIG. 2).

The machine 143 comprises an operating head 16 supported on a pedestal 18, with an operator controlled foot treadle 2% for actuating the machine starting mechanism to be described hereinafter, and an operator controlled knee pad or treadle 22 for arming the welt cut-01f mechanism and energizing the cut-ofi knife circuit as will appear hereinafter.

The operating head 16 is similar to that disclosed in the above-identified patents, and has the usual stitch-forming, shoe feeding, and welt guiding devices, a welt severing knife 24, and mechanism for activating the knife. As described in said Patent No. 2,900,933, the knife actuating mechanism includes a solenoid L-1, which is energized when a feeler 26 supported on a carrier plate 28 is en-- gaged by the end of the welt previously attached to the shoe, thereby causing the pin 30 to close switch 8-1. To avoid unintentional severing of the welt during the attaching operation, the switch 8-1 is in series with a normally open switch 8-2 which is closed by inward movement of the knee treadle 22 and the carrier plate is shifted to hold the feeler out of the range of shoe movement. The knee treadle 22 is also connected through cable 32 to the carrier plate 23, so that it is not shifted to bring the feeler into the range of movement of the shoe until the knee treadle is moved inwardly by the operator. Shifting the carrier plate, thus, moves the feeler into a position where it may be contacted by the end of the welt previously attached to the shoe.

As further described in the above-identified patents, the

operation of the welt attaching mechanism of the machine is controlled by a lock bolt 34 adapted to move into and out of engagement with an oscillating lever 36 controlling a clutch mechanism (not shown). Downward motion of the foot treadle 26 to start the machine disengages the' bolt 34 from its associated mechanism, and upward movement of the treadle to terminate the seam causes the' .disclosed in the above-identified patents, in fabricating a shoe of the sewed heel seat type, the shoe is first presented to the machine with a section along the shank.

as a starting point. The foot treadle 20 is depressed to commence the welt attaching operation, which proceeds around the periphery of the shoe, with said shoe being guided by the operator. At this time the switch 8-2 is open and the carrier is not shifted, so that the feeler 26 is not in the actuating position. As the attaching operation nears completion, the operator, without releasing the foot treadle, depresses the knee treadle, which renders the feeler operative, moves the feeler 26 into position adjacent the shoe ahead of the attaching mechanism, and closes the switch S2. As the attaching operation proeeeds, the feeler 26 eventually is contacted by the leading end ofithe welt previously attached to the shoe, which closes'the switch 3? thereby actuating the welt cutting knife. After the welt has been cut, the attaching operation continues until the short length of welt between the point of attachment and the knife (usually about /2 inch) has been attached. The feeler is so positioned that the welt is cut to the proper length to enable the cut end, when attached, to reach and abut the leading end previously attached to the shoe, and the attaching operation permittedto continue across the butt joint until about two stitches are inserted into said leading end.

' To enable a machine of this type to attach a welt about only the forepart of a shoe, some other means must be provided for energizing the knife solenoid, since in such a case there is no welt end in position to engage the feeler.

Hence, when attaching a welt to this type of shoe it is customary to provide other means to hold switch 8- in the closed position or a separate switch in parallel therewith, actuatable by the operator, so that when the operator depresses the knee treadle, closing switch 5-2,

* the cut-ofi knife is actuated immediately. In this case,

the operator must permit the machine to continue the sewing operation for only about two stitches and then release the foot treadle to stop the machine, so that proper length of the end of the welt is left unattached for later trimming operations.

.As pointed out above, considerable skill is required on the part of the operator to judge the proper instant to stop the machine, particularly in view of the fact that the attaching operation proceeds at a rate of about 800 stitches per minute. For this reason the machine disclosed herein is provided with automatically actuated mechanism for stopping'the machine a predetermined time after the actuation of the welt cut-oil knife,.with

j means for adjusting said time to suit the requirements of the particular type of shoe being fabricated. Means is also provided for actuating the machine stopping mechanism in case of thread breakage or looseness.

Referring to FIG. 6 of the drawing, there is schematically illustrated a machine having a starting and stopping mechanism which is adapted to be actuated by the operator, and auxiliary machine stopping connections actuated automatically by theaction of the welt cutting knifezd or by a thread break detecting mechanism to be described hereinafter. g

The foot treadle 28 is connected to the lock bolt 34 by a linkage which includes a toggle 40 which is normally held in the straight or unbroken position by a spring 42 connected to the knee 44 of the toggle. When the foot treadle 20.is depressed by the operator to start the welt attaching operation, a lever 46 moves the toggle 4t and operating rod 48 upwardly, thereby drawing the bolt 34 out of engagement with the clutch lever 36. To energize the machine electrical circuits as the machine is started, a main switch 8-3 is positioned to be actuated by said 'movement of the bolt.

To provide for automatic actuation of the machine stopping connections, a linkage 50 is connected to the 4. the bolt 34 again to enter the clutch lever 36 and stop the machine, and also to open the switch 5-3, to tie-energize all the machine circuits.

The treadle solenoid L-Z may be energized by either the action of the cutting knife 24, or by the action of the thread detecting mechanism in a manner to appear hereinafter. 7

To provide for automatic actuation of the treadle solenoid at the end of a sewing operation, the knife actuating solenoid armature may be provided with a cam 52, which, on the cutting stroke of the knife, is positioned to operate lever 54 to close momentarily the contacts of normally open switch 8-4. Switch 8-4, when closed, energ zes relay R-l, which closes a first pair of contacts (34 creating a holding circuit to relay R-1, and a second pair of contacts C-Z which energizes timing relay TR2. After a predetermined time, which maybe varied as will appear hereinafter, the contacts (3-3 of the'timing relay close, thereby energizing the solenoid L-2 and actuating'the mechanism previoulsy described for stopping the machine and opening the main switch 8-3 to the control circuits. As previously described, when fabricating a shoe of the sewed seat type the welt isv cut otf about A: inch'from the point of attachment. Hence, the timing relay TR-2, in such case, must permit the operation of the machine to continue until this /2 inch length of welt has been attached, plus about two stitches across the welt joint. However, in the case of a shoe in which the welt is attached about the forepart only, it is desirable to leave an unattached end for subsequent trimming operations, hence it is necessary that the machine be stopped almost immediately after the welt has been cut, with no more than about two stitches being'applied after the instant of cut-ofi to leave th proper length at the end of the welt unattached.

Hence, the time delay relay TR-Z may be adjustable to provide two difierent delay times, the duration of which will, of course, depend on the sewing speed and stitch spacing of the particular machine. As a specific example, a machine having a sewing speed of 800 stitches per minute anda stitch spacing of 4 stitches per inch Will require a delay time of 300 milliseconds when attaching a welt to breast-to-breast Work, and a delay time of 150 milliseconds when attaching a welt to sewed seat work.

Time delay relays capable of such adjustment are well known in the art and do not per se form part of the the control of the operator to enable him to preselect the t a relay having the proper delay time for the type ofwork being operated on.

The machine stopping solenoid L-2 may also be actuated directly by a switch S5 which is connected to the solenoid L2 through main switch S3. The switch S5' is positioned to be actuated by a mechanism 60 for detecting a break or looseness in the thread.

. The mechanism 69 may conveniently be associated with a thread tensioning mechanism 62, which in the illustrated embodiment is of the type disclosed in Patent No. 2,707,926, issued May 10, 1955, to O. R. Haas. As illustrated herein in FIG. 4 the thread tensioning mechanism 62 includes a take-up lever 64 centrally pivoted to a frame portion 67 and having a thread engaging V,

pulley 66 at its forward end and a cam follower 68 at its rearward end engaging a cam track 70. The thread 72 passes from a supply reel over a friction wheel (not shown) in the manner described in the above-mentioned Patent No. 2,707,926, under an idler pulley 74, over the take-up lever pulley 66 and then downwardly to the sewing mechanism.

During the sewing operation the stitches are tightened by upward movement of the forward end of the take-up lever 64 at which time the friction wheel has a heavy frictional force applied to it, so that the portion of the thread between the take-up lever pulley 66 and the idler pulley 74 is under heavy tension. When the forward end of the lever 64 moves downwardly frictional force on the tension wheel is relieved to permit the sewing mechanism to pull thread easily from the supply reel, and during this portion of the sewing cycle the portion of the thread between the take-up lever pulley 66 and the idler pulley 74 is not under any substantial tension.

To detect a thread break or thread looseness during the take-up portion of the cycle, a lever 76 which is pivoted at 77 to the machine frame is provided with a roller 78 positioned to bear against the thread between the take-up pulley and the idler pulley. The lever 76 is biased against the thread by a spring 80 attached to the end of a control arm 82 extending from the lever near the pivot 77. The machine stop switch 8-5 is disposed adjacent the end of the control arm 82 in position to be actuated by downward movement of the arm. During the take-up portion of the sewing cycle upward movement of the take-up lever pulley in cooperation with the locking of the thread friction wheel causes sufiicient tension in the thread to hold the lever 76 in the up position against the force of the spring 80 so that the control arm does not contact the switch S5. To prevent actuation of the switch S- during the next portion of the sewing cycle, while the sewing mechanism is drawing thread from the supply wheel and the thread is not under substantial tension, a lever 84 pivoted to the main frame on an axle 85 is provided with a detent roller 86 for cooperation with a recess 88 in the lower side of the control arm 82. The recess 88, which is shaped to receive the roller 86 under certain conditions, has a cam surface 89 disposed on the forward side thereof. The axle 85 is provided with an operating lever 90 on the opposite side of the frame portion 67 with said lever having a roller 92 on the forward end biased downwardly against the forward end of the take-up lever 64 by means of a spring 94. Upward and downward movement of the take-up lever 64 during the sewing cycle thereby causes forward and backward movement of the lever 84. When the take-up lever moves forwardly to apply tension to the thread the upward motion imparted to the forward end 92 of the operating lever 90 causes the detent roller 86 to move in a clockwise direction as seen in FIG. 5 so that it is positioned in the path of the recess 88 and the arm 76 is held upwardly only by the thread 72. Hence, if the thread 72 breaks during this portion of the cycle the lever 82 is pulled downwardly by spring 80 so that the control arm 82 strikes the switch S5 stopping the machine by energization of the solenoid L-2 in the manner previously described.

When the take-up lever 64 moves downwardly and the thread tension is released, the lever 84 moves in a counterclockwise direction (as seen in FIG. 5), so that the roller 86 rides under cam surface 89 on the control arm, thereby preventing downward movement of the lever 76 which would otherwise result from the release of tension in the thread, and preventing the switch S-5 from being operated during this portion of the cycle.

It will be understood that other means of detecting a thread break or looseness may be utilized if desired.

The method of operation of the machine described herein is similar to that previously described in connection with the machines of the prior art. In the attachment of a welt to a sewed seat shoe, when the knife 24 is actuated by the engagement of the feeler 26 with the leading end of the welt no further action by the operator is required until the machine stops automatically in response to the action of the timing relay, after which he may release the treadle and remove the shoe from the machine.

In the attachment of a welt in breast-to-breast work the operator must judge the proper moment to depress the knee treadle 22 (which, in this case, immediately actuates the knife). However, it is unnecessary for him to release the foot treadle to stop the sewing operation to prevent the attachment of the welt end, since the machine is stopped automatically by the timing relay within about two stitches in the manner previously described.

Since certain obvious changes may be made in the device without departing from the scope of the invention, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for attaching a length of strip material from a continuous supply to an article, said machine having an operator controlled starting and stopping mechanism and a strip cutting mechanism actuatable during the attaching operation to sever the attached portion of strip material from the continuous supply, the improvement comprising auxiliary machine stopping connections, and means responsive to the actuation of said strip cutting mechanism for actuating said auxiliary machine stopping connections.

2. A machine for attaching a length of welting from a continuous supply to a partially fabricated shoe, said machine having an operator controlled starting and stopping mechanism, a Welt cutting mechanism actuatable to sever the attached portion of the welting from the continuous supply, time delay means for actuating said machine stopping mechanism, and means responsive to the operation of said welt cutting mechanism for actuating said time delay means, whereby said machine is stopped a predetermined time after said welt is cut.

3. In a welt sewing machine for attaching a length of welting from a continuous supply to a partially fabricated shoe, said machine having a stitch forming and thread tensioning mechanism, operator controlled starting and stopping mechanism, and a welt cutting mechanism actuatable to sever the attached portion of the welt from the continuous supply, the improvement comprising an auxiliary machine stopping connections, means responsive to the operation of said welt cutting mechanism for actuating said auxiliary machine stopping connections, and means associated with said thread tensioning mechanism responsive to thread breakage for actuating said auxiliary machine stopping connections.

4. A machine as set forth in claim 3 in which said welt cutting mechanism actuates said auxiliary machine stopping connections through time delay means, and said means responsive to thread breakage actuates said auxiliary machine stopping connections directly.

5. In a welt sewing machine for attaching a length of welting from a continuous supply to a partially fabricated shoe, said machine having starting and stopping mechanism, an operator controlled treadle connected to said starting and stopping mechanism, and a welt cutting mechanism actuatable to sever the attached portion of the welt from the continuous supply, the improvement comprising a mechanical toggle linkage interposed between the treadle means and the starting and stopping means, and means responsive to actuation of said welt cutting mechanism for breaking said toggle linkage to actuate the machine stopping mechanism without the necessity of the operator releasing said treadle.

6. In a welt sewing machine for attaching a length of welting from a continuous supply to an insole, said machine having stitch forming and thread tensioning mechanism, starting and stopping mechanism, an operator controlled treadle means for actuating said starting and stopping mechanism, and a welt cutting mechanism actuatable to sever the attached portion of the Welt from the continuous supply, the improvement comprising a mechanical toggle linkage interposed between the'treadle and speaeie the starting and stopping mechanism, means for breaking said toggle linkage to actuate the machine stopping mechanism, time delay means forenergizing said means for breaking said toggle linkagefmeans responsive to actuation of said welt cutting mechanism for actuating said time delay means, and other means associated with said thread tensioning mechanism responsive to thread breakage for energizing said means for breaking said toggle linkage to actuate the machine stopping mechanisms.

Reference-s flitd" in the file 6f this patent UNITED STATES PATENTS Sept. '27, 1949 Schwartz -Apri1 6, 1954 Haas ..Ma'y 10, 1955 Carter -May 12, 1959 Carter a 7 -'Aug. 25,1959

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